Perforating Apparatus for Enhanced Performance in High Pressure Wellbores

ABSTRACT

A perforating apparatus ( 50 ) includes a carrier gun body ( 52 ) having a plurality of radially reduced sections ( 54 ). The radially reduced sections ( 54 ) have a nanocomposite outer layer ( 72 ). A charge holder ( 62 ) is positioned within the carrier gun body ( 52 ). A plurality of shaped charges ( 56 ) are supported by the charge holder ( 62 ). The shaped charges ( 56 ) each have an initiation end and a discharge end. The discharge ends of the shaped charges ( 56 ) are disposed proximate the radially reduced sections ( 54 ) of the carrier gun body ( 52 ) such that the jets formed upon detonation of the shaped charges ( 56 ) travel through the radially reduced sections ( 54 ). The nanocomposite outer layers ( 72 ) of the radially reduced sections ( 54 ) enable enhanced performance of the perforating apparatus ( 50 ) in high pressure and high temperature wellbores.

TECHNICAL FIELD OF THE INVENTION

This invention relates, in general, to an apparatus for perforatingsubterranean wellbores using shaped charges and, in particular, to aperforating apparatus for enhanced performance in high pressure and hightemperature wellbores.

BACKGROUND OF THE INVENTION

Without limiting the scope of the present invention, its background willbe described with reference to perforating a hydrocarbon bearingsubterranean formation with a shaped charge perforating apparatus, as anexample.

After drilling the section of a subterranean wellbore that traverses ahydrocarbon bearing subterranean formation, individual lengths of metaltubulars are typically secured together to form a casing string that ispositioned within the wellbore. This casing string increases theintegrity of the wellbore and provides a path through which fluids fromthe formation may be produced to the surface. Conventionally, the casingstring is cemented within the wellbore To produce fluids into the casingstring, hydraulic openings or perforations must be made through thecasing string, the cement and a distance into the formation.

Typically, these perforations are created by detonating a series ofshaped charges located within one or more perforating guns that aredeployed within the casing string to a position adjacent to the desiredformation Conventionally, the perforating guns are formed from a closed,fluid-tight hollow carrier gun body adapted to be lowered on a wire lineor tubing conveyed into the wellbore. Disposed within the hollow carriergun body is a charge holder that supports and positions the shapedcharges in a selected spatial distribution. The shaped charges haveconically constrained explosive material therein. A detonating cord thatis used to detonate the shaped charges is positioned adjacent to therear of the shaped charges. The detonating cord can be activatedelectronically or mechanically when the perforating gun has beenpositioned in the wellbore.

In such closed, fluid-tight type gun bodies, the explosive jets producedupon detonation of the shaped charges penetrate the hollow carrier gunbody before penetrating the casing wall of the wellbore and the adjacentformation. To reduce the resistance produced by the hollow carrier gunbody and increase the depth of perforation penetration into and theformation, the perforating gun body may be provided with scallops orother radially reduced sections such as bands that leave relatively thinwall portions through which the explosive jets pass. The scallops in thehollow carrier gun body must be positioned in a spatial distributionthat corresponds to the spatial distribution of the shaped charges heldwithin the gun body by the charge holder.

It has been found, however, that the reduction in thickness of thecarrier gun body at and near the scallops, limits the strength of theperforating guns. Thus, to perforate in certain high pressure and hightemperature wellbores, perforating guns of a given outer diameter musthave increased wall thickness and/or reduced scallop depth. In eithercase, the performance of such perforating guns is diminished.Specifically, use of a carrier gun body with increased wall thicknessreduces the available volume within the carrier gun body whichnecessitates the use of smaller shaped charges. Likewise, use of acarrier gun body with reduced scallop depth limits the penetration depthof the perforations into the formation.

A need has therefore arisen for a perforating apparatus that is operablefor use in high pressure and high temperature wellbores that does notrequire a carrier gun body with increased wall thickness. A need hasalso arisen for such a perforating apparatus that is operable for use inhigh pressure and high temperature wellbores that does not require acarrier gun body with reduced scallop depth. Further, a need has arisenfor such a perforating apparatus that is operable to achieve enhancedperforating performance in high pressure and high temperature wellbores.

SUMMARY OF THE INVENTION

The present invention disclosed herein comprises a perforating apparatusfor enhancing perforating performance in high pressure and hightemperature wellbores. The perforating apparatus of the presentinvention is operable for use in high pressure and high temperaturewellbores without requiring a carrier gun body with increased wallthickness. In addition, the perforating apparatus of the presentinvention is operable for use in high pressure and high temperaturewellbores without requiring a carrier gun body with reduced scallopdepth.

In one aspect, the present invention is directed to a perforatingapparatus for high pressure and high temperature applications. Theperforating apparatus includes a carrier gun body having a plurality ofradially reduced sections that have a nanocomposite outer layer. Acharge holder is positioned within the carrier gun body. A plurality ofshaped charges are supported by the charge holder. The shaped chargeseach have an initiation end and a discharge end and are positioned suchthat the discharge ends are disposed proximate the radially reducedsections of the carrier gun body.

In one embodiment, the radially reduced sections of the carrier gun bodyare recesses. In another embodiment, the radially reduced sections ofthe carrier gun body are bands. In certain embodiments, the use of ananocomposite outer layer is not limited to the radially reducedsections of the carrier gun body. For example, a portion of the carriergun body proximate the radially reduced sections may have ananocomposite outer layer. Likewise, the entire carrier gun body mayhave a nanocomposite outer layer. Alternatively or additionally, thecarrier gun body may have a nanocomposite inner layer or may be formedentirely from a nanocomposite material

In one embodiment, the nanocomposite material that forms all or part ofthe carrier gun body may be a nanostructured alloy such as ananostructured iron based alloy. In this embodiment, the iron basedalloy may be derived from metallic glass. Also, in this embodiment, thealloying constituents of the iron based alloy may be selected from thegroup consisting of boron, carbon, chromium, iron, manganese,molybdenum, nickel, niobium, silicon, tungsten and vanadium.

In one embodiment, the nanocomposite layers may be applied to thecarrier gun body by a thermal spraying process. In another embodiment,the nanocomposite layers may be applied to the carrier gun body by awelding process. In additional embodiments, the nanocomposite layers maybe integral with the carrier gun body material.

In another aspect, the present invention is directed to a perforatingapparatus for high pressure and high temperature applications. Theperforating apparatus includes a carrier gun body having an outersurface that is at least partially formed from a nanocomposite material.A charge holder is positioned within the carrier and a plurality ofshaped charges are supported by the charge holder.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the features and advantages of thepresent invention, reference is now made to the detailed description ofthe invention along with the accompanying figures in which correspondingnumerals in the different figures refer to corresponding parts and inwhich:

FIG. 1 is a schematic illustration of an offshore oil and gas platformoperating a perforating apparatus according to an embodiment of thepresent invention;

FIG. 2 is partial cut away view of a perforating apparatus according toan embodiment of the present invention;

FIG. 3 is partial cut away view of a perforating apparatus according toan embodiment of the present invention;

FIG. 4 is a cross sectional view of a carrier gun body of a perforatingapparatus according to an embodiment of the present invention;

FIG. 5 is a cross sectional view of a carrier gun body of a perforatingapparatus according to an embodiment of the present invention;

FIG. 6 is a cross sectional view of a carrier gun body of a perforatingapparatus according to an embodiment of the present invention;

FIG. 7 is a cross sectional view of a carrier gun body of a perforatingapparatus according to an embodiment of the present invention;

FIG. 8 is a cross sectional view of a carrier gun body of a perforatingapparatus according to an embodiment of the present invention; and

FIG. 9 is a cross sectional view of a carrier gun body of a perforatingapparatus according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

While the making and using of various embodiments of the presentinvention are discussed in detail below, it should be appreciated thatthe present invention provides many applicable inventive concepts whichcan be embodied in a wide variety of specific contexts. The specificembodiments discussed herein are merely illustrative of specific ways tomake and use the invention, and do not delimit the scope of the presentinvention.

Referring initially to FIG. 1, a perforating apparatus of the presentinvention is operating from an offshore oil and gas platform isschematically illustrated and generally designated 10. Asemi-submersible platform 12 is centered over a submerged oil and gasformation 14 located below sea floor 16. A subsea conduit 18 extendsfrom deck 20 of platform 12 to wellhead installation 22 includingblowout preventers 24. Platform 12 has a hoisting apparatus 26 and aderrick 28 for raising and lowering pipe strings such as work sting 30.

A wellbore 32 extends through the various earth strata includingformation 14. A casing 34 is cemented within wellbore 32 by cement 36.Work string 30 includes various tools including shaped chargeperforating apparatus 38 that is operable to enhance perforatingperformance in high pressure and high temperature wellbores. When it isdesired to perforate formation 14, work string 30 is lowered throughcasing 34 until shaped charge perforating apparatus 38 is positionedadjacent to formation 14. Thereafter, shaped charge perforatingapparatus 38 is fired by detonating the shaped charges that are disposedwithin carrier gun body 40 and aligned with recesses 42 formed in theouter surface of carrier gun body 40. In the present invention, at leastthe outer surface of each recess 42 includes a nanocomposite layer thatincreases the strength of carrier gun body 40 at the location of eachrecess 42. Use of the nanocomposite outer layer allows carrier gun body40 to have a relatively thin wall at the location of each recess 42,thereby enhancing perforating performance in high pressure and hightemperature wellbores. As such, upon detonation, the liners of theshaped charges form jets that pass through recesses 42 and form a spacedseries of perforations extending outwardly through casing 34, cement 36and a desired depth into formation 14.

Even though FIG. 1 depicts a vertical well, it should be understood bythose skilled in the art that the shaped charge perforating apparatus ofthe present invention is equally well-suited for use in wells havingother configurations including deviated wells, inclined wells,horizontal wells, multilateral wells and the like. Accordingly, use ofdirectional terms such as “above”, “below”, “upper”, “lower” and thelike are used for convenience in referring to the illustrations. Also,even though FIG. 1 depicts an offshore operation, it should beunderstood by those skilled in the art that the shaped chargeperforating apparatus of the present invention is equally well-suitedfor use in onshore operations.

Referring now to FIG. 2, therein is depicted a shaped charge perforatingapparatus of the present invention that is generally designated 50.Perforating apparatus 50 includes a carrier gun body 52 made of acylindrical sleeve having a plurality of radially reduced areas depictedas scallops or recesses 54. Radially aligned with each of the recesses54 is a respective one of a plurality of shaped charges 56. Each of theshaped charges 56 includes an outer housing, such as housing 58, and aliner, such as liner 60. Disposed between each housing and liner is aquantity of high explosive.

The shaped charges 56 are retained within carrier gun body 52 by acharge holder 62 which includes an outer charge holder sleeve 64, aninner charge holder sleeve 66. In this configuration, outer tube 64supports the discharge ends of shaped charges 56, while inner tube 66supports the initiation ends of shaped charges 56. Disposed within innertube 66 is a detonator cord 70, such as a Primacord, which is used todetonate shaped charges 56. In the illustrated embodiment, theinitiation ends of shaped charges 56 extend across the centrallongitudinal axis of perforating apparatus 50 allowing detonator cord 70to connect to the high explosive within shaped charges 56through anaperture defined at the apex of the housings of shaped charges 56.

Each of the shaped charges 56 is longitudinally and radially alignedwith one of the recesses 54 in carrier gun body 52 when perforatingapparatus 50 is fully assembled. In the illustrated embodiment, shapedcharges 56 are arranged in a spiral pattern such that each shaped charge56 is disposed on its own level or height and is to be individuallydetonated so that only one shaped charge is fired at a time. It shouldbe understood by those skilled in the art, however, that alternatearrangements of shaped charges may be used, including cluster typedesigns wherein more than one shaped charge is at the same level and isdetonated at the same time, without departing from the principles of thepresent invention. As discussed below, each of the recesses 54 ofperforating apparatus 50 has a nanocomposite outer layer 72 thatincreases the strength of carrier gun body 52, thereby enablingperforating apparatus 50 to be operable in high pressure and hightemperature wellbores.

Referring now to FIG. 3, therein is depicted a shaped charge perforatingapparatus of the present invention that is generally designated 100.Perforating apparatus 100 includes a plurality of shaped charges 102 ofwhich three are pictured. Shaped charges 102 are mounted within a chargeholder 104 that is positioned within a carrier gun body 106. In theillustrated embodiment, charge holder 104 may including one or morelongitudinal sections, each of which are rotatably supported in carriergun body 106 by a pair of supports 108, only one such support 108 beingvisible in FIG. 2. Each of the supports 108 includes rolling elements orbearings 110 contacting the interior of carrier gun body 106. Inaddition, optional thrust bearings 112 may be positioned betweensupports 108 at each end of carrier gun body 106 and devices 114attached at each end of carrier gun body 106. Devices 114 may be tandemsused to couple two guns to each other, a bull plug used to terminate agun string, a firing head or any other type of device which may beattached to a carrier gun body 106 in a gun string. In thisconfiguration, charges 102 are permitted to rotate within carrier gunbody 106.

In the illustrated embodiment, gravity is used to rotate charges 102within carrier gun body 106 to the desired orientation. Specifically, bylaterally offsetting the center of gravity of a rotating assembly 118that includes charge holder 104, shaped charges 102 and weights 120,assembly 118 is biased by gravity to rotate to a specific position inwhich the center of gravity is located directly below the rotationalaxis.

Carrier gun body 106 is provided with radially reduced portions depictedas bands 122. Bands 122 extend circumferentially about carrier gun body106 outwardly overlying each of the charges 102. Thus, as each of theshaped charges 102 rotates within carrier gun body 106, they remaindirected to shoot through one of the bands 122. As with recesses 54 ofperforating apparatus 50 discussed above, bands 122 have a nanocompositeouter layer 124 that increases the strength of carrier gun body 106,thereby enabling perforating apparatus 100 to be operable in highpressure and high temperature wellbores.

Referring now to FIG. 4, therein is depicted, in cross section, aportion of a carrier gun body of a perforating apparatus of the presentinvention that is generally designated 150. Carrier gun body 150includes a plurality of radially reduced areas 152 which may representscallops, recesses or bands such as those discussed above or otherconfigurations in which the wall of carrier gun body 150 has certainthin wall portions. Each radially reduced area 152 has a nanocompositeouter layer 154 that increases the strength of carrier gun body 150,thereby enabling a perforating apparatus including carrier gun body 150to be operable in high pressure and high temperature wellbores.

Nanocomposite outer layers 154 have a strength that is greater than thestrength of the metal forming the remainder of carrier gun body 150 Forexample, the carrier gun body 150 may be formed from conventional steelwhile nanocomposite outer layers 154 are formed from a nanostructuredmaterial having nanosized features such as nanograined iron alloysincluding nanograined steels. As used herein, a nanostructured materialwill include materials having features from 1 to 500 nanometers and morepreferably materials having features from 1 to 100 nanometers.

Nanocomposite outer layers 154 may be formed from an iron based alloyhaving alloying constituents selected from the group consisting ofboron, carbon, chromium, iron, manganese, molybdenum, nickel, niobium,silicon, tungsten and vanadium. In one example, the weight percents ofthe alloying constituents are between about 0% and 4% boron, betweenabout 0.1% and 8% carbon, between about 0.5% and 21% chromium, betweenabout 55% and 95% iron, between about 0% and 3% manganese, between about0.5% and 8% molybdenum, between about 0% and 5% nickel, between about 0%and 4% niobium, between about 0% and 2% silicon, between about 0% and 7%tungsten and between about 0% and 4% vanadium.

The material of nanocomposite outer layers 154 may be formed using aself-assembling phenomenon in solid state transformations involvingdecomposition of single phase supersaturated solid solutions intomultiphase nanoscale microstructures. The self-assembled solid statenanostructures can be prepared using a variety of techniques includingspinodal decomposition, eutectoid transformations, glass devitrificationand the like. Alternatively, the material of nanocomposite outer layers154 may be formed by using mechanical alloying of powdered metals.Preferably, the material of nanocomposite outer layers 154 is formedusing a glass devitrification process wherein the alloying constituentsof the iron based system are heat treated in a metallic glass state thendevitrified into a material having the desired multiphase nanoscalegrain structure.

Nanocomposite outer layers 154 may be applied to or formed on carriergun body 150 using a variety of processing techniques including thermalspraying processes, welding processes or other suitable techniques ormay be integrally formed with carrier gun body 150. For example,nanocomposite outer layers 154 may be applied to the carrier gun body150 using a high velocity oxy fuel (HVOF) thermal spraying process thatutilizes a combination of oxygen and one or more combustion gases suchas hydrogen, propane, propylene, kerosene and the like to spray on thenanocomposite layer. Likewise, a twin wire arc spraying (TWAS) processmay be used wherein two electrically opposed charged metal wires are fedtogether to produce a controlled arc at their intersection to form amolten metal which is atomized and propelled onto the carrier gun body150 by jets of compressed air or gas to form the nanocomposite layer.

Alternatively, nanocomposite outer layers 154 may be applied to orformed on carrier gun body 150 using a variety of welding processes. Forexample, a plasma transfer arc welding (PTAW) process utilizes plasma tomelt feedstock powder and form a fully dense and metallurgically bondedweld layer of the nanocomposite material on the carrier gun body 150.Likewise, a gas metal arc welding (GNAW) process utilizes a continuousconsumable wire electrode and a shielding gas which are fed through awelding torch such that an electric arc is transferred between the wireelectrode and the surface of the carrier gun body 150 and melts the wireto form the nanocomposite layer. Similarly, an open arc welding (OAW)process utilizes a continuous consumable wire electrode that is fedthrough a welding torch while an electric arc transferred between thewire electrode and the carrier gun body 150 melts the wire to form thenanocomposite layer.

Use of nanocomposite outer layers 154 in the radially reduced areas 152of carrier gun body 150 enables enhanced perforating performance in highpressure and high temperature wellbores by increasing the strength ofcarrier gun body 150 at the radially reduced areas 152. In addition,nanocomposite outer layers 154 increase the survivability of carrier gunbody 150 following the perforation event by minimizing swelling,cracking, catastrophic rupturing or splitting of carrier gun body 150.

Referring now to FIG. 5, therein is depicted, in cross section, aportion of a carrier gun body of a perforating apparatus of the presentinvention that is generally designated 160. Carrier gun body 160includes a plurality of radially reduced areas 162 which may representscallops, recesses or bands such as those discussed above or otherconfigurations in which the wall of carrier gun body 160 has certainthin wall portions. Each radially reduced area 162 as well as the areaproximate each radially reduced area 162 has a nanocomposite outer layer164 that increases the strength of carrier gun body 160, therebyenabling a perforating apparatus including carrier gun body 160 to beoperable in high pressure and high temperature wellbores.

As with nanocomposite outer layers 154 discussed above, nanocompositeouter layers 164 have a strength that is greater than the strength ofthe metal forming the remainder of carrier gun body 160 and may beformed from a nanostructured material having nanosized features such asthe nanograined iron alloys discussed above. Nanocomposite outer layers164 may be applied to or formed on carrier gun body 160 using a varietyof processes such as those discussed above including thermal sprayingand welding processes or may be integrally formed with carrier gun body160.

Use of nanocomposite outer layers 164 in and around radially reducedareas 162 of carrier gun body 160 enables enhanced perforatingperformance in high pressure and high temperature wellbores byincreasing the strength of carrier gun body 160. In addition,nanocomposite outer layers 164 increase the survivability of carrier gunbody 160 following the perforation event by minimizing swelling,cracking, catastrophic rupturing or splitting of carrier gun body 160.

Referring now to FIG. 6, therein is depicted, in cross section, aportion of a carrier gun body of a perforating apparatus of the presentinvention that is generally designated 170. Carrier gun body 170includes a plurality of radially reduced areas 172 which may representscallops, recesses or bands such as those discussed above or otherconfigurations in which the wall of carrier gun body 170 has certainthin wall portions. The outer surface of carrier gun body 170 has ananocomposite outer layer 174 that increases the strength of carrier gunbody 170, thereby enabling a perforating apparatus including carrier gunbody 170 to be operable in high pressure and high temperature wellbores.

As with nanocomposite outer layers 154, 164 discussed above,nanocomposite outer layer 174 has a strength that is greater than thestrength of the metal forming the remainder of carrier gun body 170 andmay be formed from a nanostructured material having nanosized featuressuch as the nanograined iron alloys discussed above. Nanocomposite outerlayer 174 may be applied to or formed on carrier gun body 170 using avariety of processes such as those discussed above including thermalspraying and welding processes or may be integrally formed with carriergun body 170.

Use of nanocomposite outer layer 174 of carrier gun body 170 enablesenhanced perforating performance in high pressure and high temperaturewellbores by increasing the strength of carrier gun body 170. Inaddition, nanocomposite outer layer 174 increases the survivability ofcarrier gun body 170 following the perforation event by minimizingswelling, cracking, catastrophic rupturing or splitting of carrier gunbody 170.

Referring now to FIG. 7, therein is depicted, in cross section, aportion of a carrier gun body of a perforating apparatus of the presentinvention that is generally designated 180. Carrier gun body 180includes a plurality of radially reduced areas 182 which may representscallops, recesses or bands such as those discussed above or otherconfigurations in which the wall of carrier gun body 180 has certainthin wall portions. The inner surface of carrier gun body 180 has ananocomposite layer 184 that increases the strength of carrier gun body180, thereby enabling a perforating apparatus including carrier gun body180 to be operable in high pressure and high temperature wellbores.

As with nanocomposite outer layers 154, 164, 174 discussed above,nanocomposite inner layer 184 has a strength that is greater than thestrength of the metal forming the remainder of carrier gun body 180 andmay be formed from a nanostructured material having nanosized featuressuch as the nanograined iron alloys discussed above. Nanocomposite innerlayer 184 may be applied to or formed on carrier gun body 180 using avariety of processes such as those discussed above including thermalspraying and welding processes or may be integrally formed with carriergun body 180.

Use of nanocomposite inner layer 184 of carrier gun body 180 enablesenhanced perforating performance in high pressure and high temperaturewellbores by increasing the strength of carrier gun body 180. Inaddition, nanocomposite inner layer 184 increases the survivability ofcarrier gun body 180 following the perforation event by minimizingswelling, cracking, catastrophic rupturing or splitting of carrier gunbody 180.

Referring now to FIG. 8, therein is depicted, in cross section, aportion of a carrier gun body of a perforating apparatus of the presentinvention that is generally designated 190. Carrier gun body 190includes a plurality of radially reduced areas 192 which may representscallops, recesses or bands such as those discussed above or otherconfigurations in which the wall of carrier gun body 190 has certainthin wall portions. Each radially reduced area 192 has a nanocompositeouter layer 194 and the inner surface of carrier gun body 190 has ananocomposite layer 196 that increase the strength of carrier gun body190, thereby enabling a perforating apparatus including carrier gun body190 to be operable in high pressure and high temperature wellbores.

As with the nanocomposite outer layers discussed above, nanocompositelayers 194, 196 have a strength that is greater than the strength of themetal forming the remainder of carrier gun body 190 and may be formedfrom a nanostructured material having nanosized features such as thenanograined iron alloys discussed above. Nanocomposite layers 194, 196may be applied to or formed on carrier gun body 190 using a variety ofprocesses such as those discussed above including thermal spraying andwelding processes or may be integrally formed with carrier gun body 190.

Use of nanocomposite layers 194, 196 of carrier gun body 190 enablesenhanced perforating performance in high pressure and high temperaturewellbores by increasing the strength of carrier gun body 190. Inaddition, nanocomposite layers 194, 196 increase the survivability ofcarrier gun body 190 following the perforation event by minimizingswelling, cracking, catastrophic rupturing or splitting of carrier gunbody 190.

Referring now to FIG. 9, therein is depicted, in cross section, aportion of a carrier gun body of a perforating apparatus of the presentinvention that is generally designated 200. Carrier gun body 200 isformed from a nanocomposite material 202 that has a strength greaterthan a similarly dimensioned carrier gun body formed from conventionalmaterials, thereby enabling a perforating apparatus including carriergun body 200 to be operable in high pressure and high temperaturewellbores. As with the nanocomposite layers discussed above,nanocomposite material 202 may be formed from a nanostructured materialhaving nanosized features such as the nanograined iron alloys discussedabove. In addition to enhancing perforating performance, carrier gunbody 200 formed from nanocomposite material 202 increases thesurvivability of carrier gun body 200 following the perforation event byminimizing swelling, cracking, catastrophic rupturing or splitting ofcarrier gun body 200.

While this invention has been described with reference to illustrativeembodiments, this description is not intended to be construed in alimiting sense. Various modifications and combinations of theillustrative embodiments as well as other embodiments of the invention,will be apparent to persons skilled in the art upon reference to thedescription. It is, therefore, intended that the appended claimsencompass any such modifications or embodiments.

1. A perforating apparatus comprising: a carrier gun body having aplurality of radially reduced sections, the radially reduced sectionshaving a nanocomposite outer layer; a charge holder positioned withinthe carrier gun body; and a plurality of shaped charges supported by thecharge holder, the shaped charges each having an initiation end and adischarge end, the discharge ends being disposed proximate the radiallyreduced sections of the carrier gun body.
 2. The perforating apparatusas recited in claim 1 wherein the radially reduced sections furthercomprise recesses.
 3. The perforating apparatus as recited in claim 1wherein the radially reduced sections further comprise bands.
 4. Theperforating apparatus as recited in claim 1 wherein at least a portionof the carrier gun body proximate the radially reduced sections furthercomprises a nanocomposite outer layer.
 5. The perforating apparatus asrecited in claim 1 wherein the carrier gun body further comprises ananocomposite outer layer.
 6. The perforating apparatus as recited inclaim 1 wherein the carrier gun body further comprises a nanocompositeinner layer.
 7. The perforating apparatus as recited in claim 1 whereinthe nanocomposite outer layers of the radially reduced sections furthercomprise a nanostructured alloy.
 8. The perforating apparatus as recitedin claim 1 wherein the nanocomposite outer layers of the radiallyreduced sections further comprise an iron based alloy.
 9. Theperforating apparatus as recited in claim 8 wherein the iron based alloyis derived from metallic glass.
 10. The perforating apparatus as recitedin claim 8 wherein alloying constituents of the iron based alloy areselected from the group consisting of boron, carbon, chromium, ironsmanganese, molybdenum, nickel, niobium, silicon, tungsten and vanadium.11. The perforating apparatus as recited in claim 1 wherein thenanocomposite outer layers are applied to the radially reduced sectionsby a thermal spraying process.
 12. The perforating apparatus as recitedin claim 1 wherein the nanocomposite outer layers are applied to theradially reduced sections by a welding process.
 13. The perforatingapparatus as recited in claim 1 wherein the nanocomposite outer layersare integral with the carrier gun body material.
 14. A perforatingapparatus comprising: a carrier gun body having a surface, the surfaceat least partially formed from a nanocomposite material; a charge holderpositioned within the carrier; and a plurality of shaped chargessupported by the charge holder.
 15. The perforating apparatus as recitedin claim 14 wherein the carrier gun body has a plurality of radiallyreduced sections and wherein the nanocomposite material forms an outersurface of the radially reduced sections of the carrier gun body. 16.The perforating apparatus as recited in claim 15 wherein thenanocomposite material forms an outer surface of at least a portion ofthe carrier gun body proximate the radially reduced sections.
 17. Theperforating apparatus as recited in claim 14 wherein the surface of thecarrier gun body further comprises an outer surface.
 18. The perforatingapparatus as recited in claim 14 wherein the surface of the carrier gunbody further comprises an inner surface.
 19. The perforating apparatusas recited in claim 14 wherein the carrier gun body is entirely formedfrom nanocomposite material.
 20. The perforating apparatus as recited inclaim 14 wherein the nanocomposite material further comprises ananostructured alloy.
 21. The perforating apparatus as recited in claim14 wherein the nanocomposite material further comprises an iron basedalloy.
 22. The perforating apparatus as recited in claim 21 wherein theiron based alloy is derived from a metallic glass.
 23. The perforatingapparatus as recited in claim 21 wherein alloying constituents of theiron based alloy are selected from the group consisting of boron,carbon, chromium, iron, manganese, molybdenum, nickel, niobium, silicon,tungsten and vanadium.
 24. The perforating apparatus as recited in claim14 wherein the nanocomposite material is applied to the carrier gun bodyby a thermal spraying process.
 25. The perforating apparatus as recitedin claim 14 wherein the nanocomposite material is applied to the carriergun body by a welding process.
 26. The perforating apparatus as recitedin claim 14 wherein the nanocomposite material is integral with thecarrier gun body material.